Inflatable quonset and domed structures and the like

ABSTRACT

A pneumatically inflatable structure includes first and second parallel spaced apart pneumatic end support tubes and at least two opposed pairs of bowed criss-crossed pneumatic bracing tubes and an arched canopy extending over the support tubes and bracing tubes. Each of the end support tubes has first and second opposed ends each mountable to a base surface wherein each of the end support tubes forms a vertical arch having an apex when the structure is erect. The pneumatic bracing tubes have first and second ends wherein each of the first ends of the bracing tubes are secured to one of the first or second ends of one of the first or second end support tubes. Each of the second ends of the pneumatic bracing tubes are securable to substantially the apex or thereabouts of an opposed tube of the first or second end support tubes.

CROSS REFERENCE TO RELATED APPLICATION

This application is a continuation-in-part of and claims priority from U.S. patent application Ser. No. 12/078,644 filed Apr. 2, 2008 entitled Inflatable Structure for Covering Sport Utility Vehicles, Boats and the Like.

FIELD OF THE INVENTION

This invention relates to the field of inflatable structures including tents and in particular to an inflatable quonset-shaped, domed or other structure useful as an event venue, portable temporary shelter, or covering for mid to large sized objects including vehicles, boats and the like.

BACKGROUND OF THE INVENTION

Inflatable tents for use in camping are known in the prior art and are sold commercially by for example Airzone Recreation Products of Kelowna, British Columbia, Canada. Such tents typically replicate camping tents available commercially which rely on bent fibreglass poles for their support structure and instead substitute inflatable poles which, when bent into an arch, provide the supporting framework for the exterior fabric skin or canopy of the tent over which a so-called fly sheet may be mounted. In the other extreme, large tents are known in the prior art for use such as by the military for providing field barracks, field hospitals and various depot facilities, such tents often being made of canvas and supported on tubular metal-pole supporting structures.

Applicant believes that a commercial need exists for relatively large pneumatically inflatable tent-like structures which are larger than conventional recreational camping tents and easier to erect than military-style field tents. It is believed that such structures will find commercial acceptance and use by the owners of large for example sport utility vehicles, boats, trailers, and other wheeled vehicles or towables which ordinarily would require a large garage or shed for their safe storage and which are often not housed in, for example, conventional residential homes as not having extended garage facilities. Also applicant believes that commercial acceptance and use of such larger pneumatically inflatable tent-like structures may include those in the field of portable corporate sponsorship pavilions for example for use in trade-shows, portable pneumatically inflatable recreational and professional sports shelters for sheltering equipment, non-engaged players, or sickly or wounded players on for example the side-lines of a sports field, portable warehouses, etc.

What is required, is a relatively larger pneumatically inflatable structure which may be readily transportable in that, when collapsed, the structure is not exceedingly heavy or overly bulky so the structure may be transported in for example the aforementioned sport utility vehicles, or in the beds of trucks and the like, and for example may be carried to a convenient location for their use, and wherein the structure may be erected using for example a high volume, low pressure stand-alone air compressor or one running for example on mains power or from the twelve volt power source of the vehicle used to transport the collapsed structure.

In the prior art applicant is aware of the following issued patents illustrating aspects of the state of the art in pneumatically erectable structures including tents:

U.S. Pat. No. 2,591,829 which issued April 1952 to Katzenmeyer et al.; U.S. Pat. No. 2,830,606 which issued April 1958 to Daugherty; U.S. Pat. No. 3,145,719 which issued August 1964 to Johnson; U.S. Pat. No. 3,899,853 which issued August 1975 to Wertmian; U.S. Pat. No. 3,999,333 which issued December 1976 to Amarantos; U.S. Pat. No. 4,068,418 which issued January 1978 to Masse; U.S. Pat. No. 4,197,681 which issued April 1980 to Holcombe; U.S. Pat. No. 4271642 which issued June 1981 to Karr; U.S. Pat. No. 4,709,718 which issued December 1987 to Nichols; U.S. Pat. No. 4,766,918 which issued August 1988 to Odekirk; U.S. Pat. No. 4,819,389 which issued April 1989 to Kihn; U.S. Pat. No. 4,825,892 which issued May 1989 to Norman; U.S. Pat. No. 4,876,829 which issued October 1989 to Mattick; U.S. Pat. No. 4,901,481 which issued February 1990 to Seeley, Jr.; U.S. Pat. No. 4,918,877 which issued April 1990 to Dutka; U.S. Pat. No. 5,005,322 which issued April 1991 to Mattick et al.; U.S. Pat. No. 5,007,212 which issued April 1991 to Fritts et al.; U.S. Pat. No. 5,122,400 which issued June 1992 to Stewart; U.S. Pat. No. 5,205,086 which issued April 1993 to Heim; U.S. Pat. No. 5,247,768 which issued September 1993 to Russo; U.S. Pat. No. 5,421,128 which issued June 1995 to Shapless et al.; U.S. Pat. No. 5,570,544 which issued November 1996 to Hale et al.; U.S. Pat. No. 5,636,478 which issued June 1997 to Chen; U.S. Pat. No. 5,987,822 which issued November 1999 to McNiff et al.; U.S. Pat. No. 6,014,982 which issued January 2000 to Strevey; and U.S. Pat. No. 6,263,617 which issued July 2001 to Turcot.

SUMMARY OF THE INVENTION

According to a first embodiment of the present invention there is provided a pneumatically inflatable structure comprising first and second parallel spaced apart pneumatic end support tubes and at least two opposed pairs of bowed crisscrossed pneumatic bracing tubes and an arched canopy extending over the support tubes and bracing tubes. Each of said end support tubes has first and second opposed ends each mountable to a base surface wherein each of the end support tubes forms a vertical arch having an apex when the structure is erect. The pneumatic bracing tubes have first and second ends wherein each of the first ends of the bracing tubes are secured to one of the first or second ends of one of the first or second end support tubes. Each of the second ends of the pneumatic bracing tubes are securable to substantially the apex or thereabouts of an opposed of the first or second end support tubes.

The array of the pneumatically inflatable structure may comprise two end support tubes and the two opposed pairs of bracing tubes may be mounted thereto and extend therebetween. The array may further comprise at least one intermediate support tube forming a vertical arch between and in parallel to the end support tubes for example at a location where one of the at least one intermediate support tubes intersects a junction of the bracing tubes where the bracing tubes criss-cross. The support tubes and bracing tubes may have equal length. In one embodiment the support tubes and tire bracing tubes may be substantially identical.

In a further embodiment the support tubes may be grouped and mounted to each other in bundles, for example in bundles of three tubes, so that each set of bundles of tubes form a multi-tube support beam. Each multi-tube beam may be a flat beam wherein the plurality of tubes in the beam are parallel, adjacent and contiguous to one another in a flat side-by-side array lying in the plane of curvature containing the arch and wherein the side-by-side array is orthogonal to the plane of curvature. Thus in one embodiment each arch is a curved beam having three side-by-side single tubes mounted to one another, for example within a single outer casing, wherein preferably the casing is divided into longitudinally extending substantially tubular side-by-side compartments to maintain the single tubes adjacent and parallel to one another and in one embodiment to stiffen the bundle to resist for example lateral deflection while allowing bending of the beam in the plane of curvature. Alternatively the beam may be a bundle of tubes held, in cross section, within the outer casing in a triangular arrangement wherein for example an uppermost tube sits along and atop an adjacent pair of lower tubes. An array, for example somewhat evenly spaced apart, of the multi-tube beams may extend along the length of the structure, for example where used in a quonset-shaped structure having a linear ridge along the apex of the arches, or may be radially spaced apart about a vertical centroidal axis of symmetry for example where used in a domed structure. In the former, at least one pair of inflatable multi-tube bracing beams may be mounted diagonally across the spaced array of beams or otherwise, for example longitudinally parallel to the ground ridge-line, etc, in order to brace the erected structure.

The canopy may be secured to the support tubes/beams and the bracing tubes/bearns for example either over the top of the tubes, or under the tubes, that is the tubes thereby forming an exoskeleton, or as a webbing between the tubes. The pneumatically inflatable structure may further comprise securing means such as various fasteners for securing the ends of the support tubes to the base surface. The securing means may comprise a flexible or hinged fastener, and may also include ground spikes. The base surface may merely be the ground surface or may include a planar sheet, or for example strapping extending between the base ends of the tubes or beams.

The pairs of inflatable bracing beams may include at least two opposed pairs of bowed criss-crossed pneumatic bracing tubes lengthwise connected to each other. The support tubes/beams and bracing tubes/beams may advantageously be pneumatically interconnected by a flexible air conduit extending therebetween so that the entire structure may be inflated simultaneously from a single source of pressurized air. For example, the air conduit may be located along the vertex of the structure and/or may be located around or along the base of the structure.

Each support tube whether or not within a multi-tube beam and each bracing tube or beam may comprise inner resilient tubes, for example rubber inner tubes, snugly mounted or mountable within outer non-resilient straight sleeves in snugly journalled relation therethrough. Each sleeve of the outer non-resilient straight sleeves may have a seam extending linearly along its length. Each seam may be an overlapped seam having an overlapped portion within the sleeve due to inversion of the sleeve following forming of the seam wherein the overlapped portion is formed of the longitudinal edges of material forming the sleeve. The overlapped portion may be folded over so as to be disposed perpendicular to a curvature of the seam when the support tubes and bracing tubes become curved as they are inflated, being constrained at their ends where mounted to the base surface.

The support tubes and bracing tubes may be self-sealing by self-sealing means at ends of support tubes and the bracing tubes. The self-sealing means may comprise ends of the inner resilient tubes which are folded over onto themselves wherein the ends of the tubes are anchored by anchoring means to the ends of support tube sleeves. The ends of the support tubes may each be formed as a flap hinge.

The inner resilient tubes may be adapted, when mounted in the sleeves, to contain air pressurized for example up to between eight to twelve pounds per square inch.

The pneumatically inflatable structure may further comprise a canopy vestibule extending from an opening aperture into the pneumatically inflatable structure.

Other aspects and features of the present invention will become apparent to those ordinarily skilled in the art upon review of the following description of specific embodiments of the invention in conjunction with the accompanying figures.

BRIEF DESCRIPTION OF THE DRAWINGS

In drawings which illustrate embodiments of the invention wherein similar characters of reference denote corresponding parts in each view,

FIG. 1 is a perspective view of a pneumatically inflatable structure according to a first embodiment of the invention.

FIG. 2 is a perspective view of the pneumatically inflatable structure of FIG. 1 with the canopy removed.

FIG. 3 a is a side elevation view of the pneumatically inflatable structure of FIG. 2.

FIG. 3 b is a plan view of the pneumatically inflatable structure of FIG. 3 a.

FIG. 4 is a bottom plan view of the canopy of the inflatable structure of FIG. 1.

FIG. 5 is a perspective view of a pneumatically inflatable structure according to an alternative embodiment of the invention having an end vestibule.

FIG. 6 is a perspective view of a pneumatically inflatable structure according to an alternative embodiment having increased dimensions.

FIG. 7 is a detailed view of the flexible end flaps of the pneumatic tubes according to the present invention.

FIG. 8 is in perspective view a further alternative embodiment of the inflatable structure according to the present invention.

FIG. 9 is a perspective view of the inflatable structure of FIG. 8 with the canopy removed.

FIG. 10 is a side elevation view of the inflatable structure of FIG. 9.

FIG. 11 is a plan view of the inflatable structure of FIG. 9.

FIG. 12 is a perspective bottom view of the inflatable structure of FIG. 8.

FIG. 13 is a front elevation view of the inflatable structure of FIG. 9.

FIG. 14 is the view of FIG. 8 showing a multiplicity of vehicles closely parked therein.

FIG. 15 is a sectional view along line 15-15 in FIG. 11.

FIG. 16 is a sectional view along line 16-16 in FIG. 11.

FIG. 17 is in partially cut away partially exploded view, one overlapping end-to-end joint between a pair of tubes in a multi-tube beam according to one aspect of the present invention.

FIG. 18 is, in perspective view, a further alternative embodiment of the inflatable structure according to the present invention.

DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION

Referring to FIGS. 1-4, a pneumatically inflatable structure according to a first embodiment of the invention is shown generally at 10. The pneumatically inflatable structure 10 includes two parallel spaced apart pneumatic end support tubes 12 and two opposed pairs 20 of bowed and criss-crossed pneumatic bracing tubes 22 covered by a canopy 30. In one embodiment of the invention, end support tubes 12 and bracing tubes 22 are substantially identical as better described below. The pneumatically inflatable structure 10 may also include a base surface such as base sheet 16.

The pneumatic end support tubes 12 include ends 12 a secured to base sheet 16 or to the ground and are bowed when inflated so as to have an apex 18 be also downwardly concave. The pneumatic support tubes 12 are arranged in parallel to each other so as to define a common opening 8 thereunder sized for mid to large sized vehicles, boats and the like, or for other appropriate use as described herein. The pneumatically inflatable structure 10 may also include one or more intermediate support tube 13 secured to the base sheet or ground which are oriented and bowed in parallel to the end support tubes and so as to also have an apex 18. As illustrated in FIG. 2, one intermediate support tube 13 is utilized and located at the junctions 24 of the two pairs of the bracing tubes, although it will be appreciated, such as illustrated, that more than one intermediate support tube may also be utilized at different locations between the end support tubes 12. Advantageously tubes 12 and 13 form a substantially parallel spaced apart array of curved supports having substantially the same height and width dimensions for each of the curved supports.

Each pair 20 of pneumatic bracing tubes 22 are criss-crossed at corresponding junctions 24 in fluid communication with one another by a cooperating hollow flexible conduit such as air hose 26. The first and second opposite ends 22 a and 22 b, respectively of tubes 22 are mounted to the end support tubes 12 at each end of structure 10. The first ends 22 a are each connected to a base 12 a for example by the use of securing means such as flexible end flap 64 formed at the end of each of the tubes. The second ends 22 b are each connected to apex 18 of the tube 12 at the opposite end of structure 10, for example by the use of flexible end flaps 64 formed at the end of each of the tubes, so that each bracing tube 22 extends the length of, and generally diagonally across each lateral side of the structure 10. The bracing tubes 22 may be secured to each other as well as to the support tubes 12 and 13 by means of securing straps 80. Securing straps 80 may comprise of cable ties, string, ropes or any other suitable strap means. Other releasable fasteners may also be employed, for example lengths of hook-and-loop fasteners.

Each of the pneumatic end support tubes 12 are bowed and arranged parallel to each other so as to form a frame, illustrated by way of example in the shape of a quonset having a downwardly concave elongate structure defining a common opening 8. Intermediate support tubes 13 are bowed and oriented in parallel to the end support tubes 12 so as to support a middle portion of the canopy 30. The pneumatic bracing tubes 22 extend between and brace the end support tubes 12 so as to maintain them in their desired parallel orientation. Thus taken in combination the two opposed pairs 20 of pneumatic bracing tubes 22 and the end support tubes 12 define an elongate open enclosure elongate along longitudinal axis A.

Referring to FIG. 4, canopy 30 comprises a rectangular substantially planar flexible sheet of material having first and second end edges 32 and 34, respectively and first and second side edges 36 and 38, respectively. The canopy includes a plurality of securing straps 40 attached to a bottom surface thereof. The securing straps 40 comprise an elongate strip of material having first and second fastenable portions 42 and 44, respectively. The first and second fastenable portions may be secured to each other after the securing strip encircles one or more of the end or intermediate support tubes 12 or 13 or the bracing tubes 22 and serve to secure the canopy 30 thereto.

As illustrated in FIG. 1, the canopy 30 may also include end flanges 46 extending radially inwardly from the end support tubes 12 so as to surround the opening 8. Canopy 30 has an exterior surface 31 to which one or more guy loops 33 may be attached for securing a conventional pegged guy wire 35 thereto. It will be appreciated that the guy wires 35 will assist in the lateral stability of the inflated structure 10, in particular when subjected to side loads such as from the wind.

In an alternative embodiment as illustrated in FIG. 5, the canopy 30 may include a vestibule 50 extending from one or both ends. The vestibule 50 comprises a sheet of material extending from the first or second edge 32 or 34 of canopy 30 to a ground securing location 52 at a distance from the first or second end of the structure 10. The vestibule 50 provides increased wind resistance and security to the structure. The vestibule 50 may be formed as a common sheet with the canopy 30 or may be a separate sheet that is mounted to the canopy when the structure is erected.

The inflatable structure 10 may include a base sheet 16 comprising a rectangular sheet of material to which the ends 12 a and 12 b of the end support tubes as well as the ends of the intermediate support tubes 13 and the ends 22 a of bracing tubes 22 may be secured. The base sheet 16 may provide the dimensions of the base of the inflatable structure 10 when erected. Alternatively the inflatable structure 10 may be secured to the ground by passing a fastener 60, such as for example a ground spike through an eyelet 62 in the end flaps 64 of the end or intermediate support tubes 12 or 13 or the bracing tubes 22, as illustrated in FIG. 7.

In a further embodiment of the present invention (not shown), one or more of the inflatable structures 10 as taught above may be lengthwise connected to each other to form a common modular elongate structure. Where more than one inflatable structure 10 are employed modularly and each already has a base 16 mounted to the ends of the pairs of tubes, in a further embodiment of the present invention, a separate spanning, joining or linking section is employed to join the adjacent sides of the base 16. As may be understood then, it is not necessary that the inflatable structure according to the present invention merely and only is limited to two end support tubes 12 and a single span of bracing tubes 22 as it will be understood that a further elongated enclosure may be constructed using two or more pairs of criss-crossed bracing tubes similar to pairs 20.

In a preferred embodiment, each of the criss-crossed pneumatic bracing tubes 20 of tube pairs 22, pneumatic end support tubes 12 and pneumatic intermediate support tubes 13 are of a design such as taught in my U.S. Pat. No. 6,263,617 and incorporated herein by reference such that a resilient or at least flexible inner tube is mounted within an outer flexible relatively non-resilient sleeve, and wherein such a sleeve has a folded seam along its interior circumference folded over so that the sleeve and inner tube may be constructed as a linear pole which may then be bent to accommodate the required bowed shaped to form the inflated structure. It has been found that such inflatable tubes for example having approximately a twenty inch circumference which is constant along the length of each tube may be inflated to approximately eight to twelve pounds per square inch (psi) and thereby provide sufficient rigidity for an inflatable structure which may then be used as desired for example to house wheeled vehicles or towable trailers such as a trailer and boat combination which is not intended to be limiting.

Thus in one smaller structure embodiment, the width (w) of the span between ends of the end support tubes 12 and intermediate support tubes 13 may be approximately ten feet and the longitudinal distance between the opposite end support tubes is approximately twenty feet. Accordingly the height to the apex 18 of the end and intermediate support tubes 12 and 13 will be approximately eight feet. The pneumatic end tubes and intermediate support tubes 12 and 13 respectively and pneumatic bracing tubes 22 will thus each be approximately twenty-four feet long. It will be appreciated that other lengths of the pneumatic end and intermediate support tubes 12 and 13 and pneumatic bracing tubes 22 may also be used for other desired dimensions of the inflatable structure such as described by way of example below.

In a second embodiment illustrated in FIG. 6, the end and intermediate support tubes 12 and 13 and bracing tubes 22 may be approximately forty-seven feet long. Accordingly the structure illustrated in FIG. 6 may therefore be approximately forty-six feet long, thirty-two feet wide and have a height of approximately sixteen feet.

In all embodiments, such as seen by way of example in FIG. 2, an array of interconnected airlines 70 stemming from a common manifold 72 may be used to simultaneously inflate all of the tubes, where for example separate air lines 70 are mounted in fluid communication with adjacent ends of tubes 12, 13 and 22, and a single source (not shown) of pressurized air is mounted to manifold 72. Alternatively, separate air sources may also be used for pressurizing separate zones of the structure as defined by a grouping of fluidically interconnected tubes. Alternatively, the structure 10 may include a plurality of tubes 12, 13 and 22 mounted adjacent to and in parallel to each other such that one set of tubes 12, 13 and 22 defines a first circuit while a second set of tubes 12, 13 and 22 defines a second circuit. It will be appreciated that duplication of each tube of the structure permits that structure to remain erected should a leak occur in one of the two circuits.

Referring now to FIGS. 8-18, a pneumatically inflatable structure according to a further embodiment of the invention is shown generally at 100. The pneumatically inflatable structure 100 includes two parallel spaced apart pneumatic end support beams 102 and two opposed pairs 104 of bowed and criss-crossed pneumatic bracing beams 106 covered by a canopy 108. In one embodiment of the invention, end support beams 102 and bracing beams 106 are constructed of a multiplicity of substantially identical pneumatic tubes, described above as tubes 12, 13 and 22. The pneumatically inflatable structure 100 may also include a base such as base sheet 110.

The pneumatic end support beams 102 and parallel intermediate beams 112 are secured at their ends to base 110 or to the ground and are bowed into an arch when inflated so as to each have an apex which is also downwardly concave. The pneumatic beams are arranged parallel to each other so as to define a common opening thereunder sized for a plurality of vehicles for example, or for other appropriate uses as described herein. One or more of intermediate beams 112 may be mounted to the corresponding portions of bracing beams 106 where they intersect. It will be appreciated that the bracing beams may also be longitudinally aligned for example as a ridge-line or parallel thereto also, as illustrated, more than one intermediate beam 112 may be utilized at different locations between the end support beams 102. Advantageously beams 102 and 112 form a substantially parallel somewhat evenly spaced apart array of arched supports having substantially the same height and width dimensions, as between each beam, “h” and “w” respectively for each of the arched supports.

As before, each pair 104 of diagonally aligned bracing beams 106 are criss-crossed and in fluid communication with one another by for example a cooperating hollow flexible conduit or hose (not shown). The opposite ends of bracing beams 106 are mounted to the corresponding end support beams 102 at each end of structure 100. The lower-most ends of the bracing beams are each connected to the base for example by the use of securing means such as the flexible end flap formed at the end of each of the tubes in the beam as described above. The upper ends of the diagonal bracing beams are each connected to the corresponding apex of the end support beam 102 at the opposite end of structure 100, for example again by the use of flexible end flaps formed at the end of each of the tubes in the beam. Thus each bracing beam 106 extends the length of, and generally diagonally across each lateral side of structure 100. The bracing beams 106 may be secured to each other at their juncture as well as to the intermediate beams 112 by means of securing straps or other releasable fasteners, for example lengths of hook-and-loop fasteners.

Each of the pneumatic support beams are bowed and arranged parallel to each other so as to form a frame of arched supports, illustrated in FIGS. 8-17 by way of example in the shape of a quonset, having a downwardly concave elongate structure defining a common elongate opening and in FIG. 18 a dome-shaped structure. The intermediate beams 112 in the quonset embodiment are bowed into arches and oriented in parallel to the end support beams 102 so as to support a middle portion of the canopy and to brace-up or undergrid the bracing beams. The bracing beams extend between and brace the end support beams 102 so as to maintain them and the intermediate beams 112 in their desired parallel orientation. Thus taken in combination the two opposed pairs 104 of pneumatic bracing beams 106 and the intermediate beams 112 and end support beams 102 define an elongate open enclosure along longitudinal axis A which supports canopy thereover so as to provide a shelter thereunder.

Beams 102 and 112 are examples of beams constructed according to the present invention as bundles of individual pneumatic tubes, such as individual tubes 12. The support tubes are grouped and mounted to each other in such bundles, for example in bundles of three tubes as illustrated, so that each set of bundled tubes form a multi-tube beam. Each multi-tube beam may be a flat beam such as beams 102 or 112 wherein the plurality of tubes in the beam are parallel, adjacent and contiguous to one another in a flat side-by-side array lying in the plane of curvature containing the arch, and wherein the side-by-side array is orthogonal to the planes of curvature B. In one embodiment each arch is a curved beam having three side-by-side single tubes mounted to one another within a single outer casing 114 having a circumference of approximately forty-five inches, wherein preferably the casing is divided by flexible fabric internal walls or baffles 114 b into longitudinally extending substantially tubular side-by-side compartments 114 a to maintain the individual tubes 12 adjacent and parallel to one another and to stiffen the bundle to resist for example lateral deflection while allowing bending of the beam in the plane of curvature B. In one embodiment the outer casing 114 and 114 b are made of marine grade polyester, supplied by MarChem Coated Fabrics, of New Haven, Mo., USA. The array of somewhat evenly spaced apart, multi-tube beams 102, 112 extend along the length of the structure. The multi-tube beams may be used in a structure having a linear ridge 116 along the apex of the arches, for example in a quonset-shaped structure, or may be used in a structure where the arches are radially spaced apart about a vertical centroidal axis of symmetry D for example where used in a domed structure such as seen in FIG. 18.

In FIG. 18 the beam is a bundle of substantially the same tubes 12 held, in cross section, within the outer casing in a triangular arrangement wherein for example an uppermost tube 12′ sits along and atop an adjacent pair of lower tubes 12″. Although not shown, again the tubes may be held in their positions relative to one another by means of an outer casing enclosing the length of the tubes to form a multi-tube beam.

Thus as seen in FIG. 18, each beam 102′ is comprised of a bundle of separate inflatable tubes 12′. In the illustrated example, each beam 102′ includes a pair of tubes 12″ mounted together side-by-side so as to be coextensive between their opposite first and second ends. A tube 12′ is mounted over the pair of tubes 12″ and may be co-extensive in length, or of shorter length centered on the vertex of the span of the arch, to add the enhanced support of a multi-tube beam. Tubes 12′ and 12″ form an arch extending between their opposite ends when their opposite ends are fixed to the ground or to a base. Thus with the first and second opposite ends of the tubes 12′ and 12″ constrained by being mounted to for example the outer edges of a base sheet, and advantageously, with the edges of the base sheet secured to the ground, the length of the spanning tubes dictates that they form an arch because their length is greater than the diameter of the base.

In one method of constructing the embodiments of FIGS. 1 and 18, which are not intended to be limiting, each tube in each arch is made up of two individual inflatable tubes 12′ and 12″ respectively mounted end-to-end at for example the vertex of the arch by overlapping their wedge-shaped ends 65 together. The overlapped ends 65 are sheathed in a short casing 65 a (shown in dotted outline in FIG. 17) which is itself encased within the outer casing 114 extending the length of the beam 102, 112 or 102′. In this fashion, the entire beam 102, 112 or 102′ may be constructed of a multiplicity of identical shorter, for example approximately twenty-four foot long, inflatable tubes which are used to construct, in this example, the approximately forty-eight foot long tubes 12, 12′ and 12″. Longer tubes may be constructed by using more end-to-end sections. Each separate tube may have a circumference of generally twenty-two inches for example, meaning a diameter of approximately six to seven inches, and an overall circumferential length arched between where the opposite ends of the tube are anchored to ground (that is, directly to the ground or to a base which itself may be anchored to the ground) of generally twenty-four feet. Then each tube in each beam has an aspect ratio of approximately forty-five (288 inches long:6.4 inches in diameter). The shorter inner casing 65 a may be approximately six feet long, and as a result tends to flatten the top, that is vertex or apex, of the arch formed by the beams 102 or 112. This has the advantageous effect of lowering the height of the top of the arch (which otherwise is often wasted space) and thereby forcing the walls of the arch (that is the side walls of the structure) to a more vertical orientation thereby improving the usefulness of the space in the structure adjacent the sidewalls.

Again, each tube 12′ and 12″ in each beam 102′ may be constructed having a separate flexible sleeve for each tube made of the same material as that used for outer casing 114. Each such sleeve constrains a resilient, such as rubber, inflatable inner tube or bladder mounted therein which extends the length of the sleeve. For example, each sleeve may have a circumference of approximately twenty inches and each tube may be approximately forty-eight feet long in total length (although as described above each such tube may contain two twenty-four foot long tubes mounted end-to-end). The canopy may be of the same material as the sleeves.

As will be apparent to those skilled in the art in the light of the foregoing disclosure, many alterations and modifications are possible in the practice of this invention without departing from the spirit or scope thereof. Accordingly, the scope of the invention is to be construed in accordance with the substance defined by the following claims. 

1. A pneumatically inflatable structure for supporting a canopy, the structure comprising: a plurality of spaced apart pneumatic multi-tube support beams, each of said support beams having first and second opposite ends mountable to a base surface wherein each of said support beams form an arch having an apex when said structure is inflated and erect; wherein each of said multi-tube support beams includes a plurality of adjacently mounted parallel inflatable tubes mounted to one another along their length.
 2. The structure of claim 1 further comprising at least two opposed pairs of bowed criss-crossed pneumatic multi-tube bracing beams mounted substantially diagonally across said support beams, and wherein said arches form a parallel spaced apart array.
 3. The structure of claim 1 wherein said support beams are radially spaced apart about a vertical axis.
 4. The structure of claim 2 comprising two support beams, one at each end of said array, and two opposed pairs of said bracing beams mounted thereto and extending therebetween.
 5. The structure of claim 4 wherein said support beams include at least one intermediate support beam forming a vertical arch between and in parallel to said support beams at said ends of said array.
 6. The structure of claim 5 wherein one of said intermediate support beams is mounted to said bracing beams at a junction of each said pair of said bracing beams.
 7. The structure of claim 2 wherein said support beams and said bracing beams have equal length.
 8. The structure of claim 7 wherein said support beams and said bracing beams are substantially identical.
 9. The structure of claim 2 wherein said support beams and said bracing beams are pneumatically interconnected by a flexible air conduit extending therebetween for simultaneous inflation of said structure from a single compressed air source.
 10. The structure of claim 2 wherein said inflatable tubes of said support beams and said bracing beams comprise resilient inner bladders snugly mountable within non-resilient straight sleeves in journalled relation therethrough.
 11. The structure of claim 10 wherein each sleeve of said non-resilient straight sleeves has a seam extending linearly along its length, each said seam being an overlapped seam having an overlapped portion within said sleeve due to inversion of said sleeve following forming of said seam, said overlapped portion formed of the longitudinal edges of material forming said sleeve, said overlapped portion folded over so as to be disposed perpendicular to a curvature of said seam when said inflatable supports are inflated and formed into said arches.
 12. The structure of claim 1 wherein each said tube of said inflatable tubes includes at least a pair of resilient inner-tubes mounted within corresponding sleeves and mounted end-to-end.
 13. The structure of claim 12 wherein each said inner-tube has at least one substantially wedge-shaped end, and said at least a pair of resilient inner-tubes are mounted end-to-end by overlapping of opposed facing said wedge-shaped ends of said inner-tubes.
 14. The structure of claim 1 wherein said inflatable tubes of each said beam are mounted within a flexible outer casing.
 15. The structure of claim 14 wherein said outer casing is compartmentalized to form separate elongate compartments along and within said outer casing for mounting therein of said tubes.
 16. The structure of claim 1 wherein each said beam is a flat beam having said tubes only in side-by-side adjacent planar array when laid flat and inflated.
 17. The structure of claim 16 wherein each said beam includes three said tubes.
 18. The structure of claim 1 wherein each said beam includes three said tubes.
 19. The structure of claim 2 wherein each said support beam includes three said tubes and wherein each said bracing beam includes two said tubes. 